ALBERT

Description: We present calculations of the early stages of the formation of Jupiter via core nucleated accretion and gas capture. The core begins as a seed body of about 350 kilometers in radius and orbits in a swarm of planetesimals whose initial radii range from 15 meters to 100 kilometers. We follow the evolution of the swarm by accounting for growth and fragmentation, viscous and gravitational stirring, and for drag-induced migration and velocity damping. Gas capture by the core substantially enhances the cross-section of the planet for accretion of small planetesimals. The dust opacity within the atmosphere surrounding the planetary core is computed self-consistently, accounting for coagulation and sedimentation of dust particles released in the envelope as passing planetesimals are ablated. The calculation is carried out at an orbital semi-major axis of 5.2 AU and an initial solids' surface density of 10/g/cm^2 at that distance. The results give a core mass of 7 Earth masses and an envelope mass of approximately 0.1 Earth mass after 500,000 years, at which point the envelope growth rate surpasses that of the core. The same calculation without the envelope gives a core mass of only 4 Earth masses.

Description: No abstract available

Description: No abstract available

Description: Disk disperse in a few million years, before which they must form planets. Photoevaporation and viscosity are mainly responsible for disk dispersal. EUV, FUV and X-rays have all been suggested as photoevaporation agents, disk evolutionary scenarios and predicted mass loss rates in each case differ. Stellar mass and radiation field, disk properties, magnitude of viscosity, and dust evolution all play significant roles in determining the evolution of the disk and its lifetime. Observational diagnostics of photoevaperative flows include [Nell] and perhaps [OI]. These are at present inconclusive and better diagnostics are needed.

Description: Motivation for the study is: (1) Lunar Radio Array for low frequency, high redshift Dark Ages/Epoch of Reionization observations (z =6-50, f=30-200 MHz) (2) High precision cosmological measurements of 21 cm H I line fluctuations (3) Probe universe before first star formation and provide information about the Intergalactic Medium and evolution of large scale structures (5) Does the current cosmological model accurately describe the Universe before reionization? Lunar Radio Array is for (1) Radio interferometer based on the far side of the moon (1a) Necessary for precision measurements, (1b) Shielding from earth-based and solar RFI (12) No permanent ionosphere, (2) Minimum collecting area of approximately 1 square km and brightness sensitivity 10 mK (3)Several technologies must be developed before deployment The power needed to process signals from a large array of nonsteerable elements is not prohibitive, even for the Moon, and even in current technology. Two different concepts have been proposed: (1) Dark Ages Radio Interferometer (DALI) (2)( Lunar Array for Radio Cosmology (LARC)

Description: We report on multifrequency observations performed during 2012 December-2013 August of the first narrow-line Seyfert 1 galaxy detected in gamma rays, PMN J0948+0022 (z equal to 0.5846). A gamma-ray flare was observed by the Large Area Telescope on board Fermi during 2012 December-2013 January, reaching a daily peak flux in the 0.1-100 GeV energy range of (155 plus or minus 31)10(exp 8) ph cm (exp 2) s (exp 1) on 2013 January 1, corresponding to an apparent isotropic luminosity of approximately 1.510)exp 48) erg s(exp 1). The gamma-ray flaring period triggered Swift and VERITAS observations in addition to radio and optical monitoring by OVRO, MOJAVE, and CRTS. A strong flare was observed in optical, UV, and X- rays on 2012 December 30, quasi-simultaneously to the gamma-ray flare, reaching a record flux for this source from optical to gamma rays. VERITAS observations at very high energy (E greater than 100 GeV) during 2013 January 6-17 resulted in an upper limit of F(sub greater than 0.2 TeV) less than 4.0 10(exp 12) ph cm(exp 2) s(exp 1). We compared the spectral energy distribution (SED) of the flaring state in 2013 January with that of an intermediate state observed in 2011. The two SEDs, modelled as synchrotron emission and an external Compton scattering of seed photons from a dust torus, can be modelled by changing both the electron distribution parameters and the magnetic field.

Description: The architecture of a cross-correlator for a synthesis radio telescope with N greater than 1000 antennas is studied with the objective of minimizing power consumption. It is found that the optimum architecture minimizes memory operations, and this implies preference for a matrix structure over a pipeline structure and avoiding the use of memory banks as accumulation registers when sharing multiply-accumulators among baselines. A straw-man design for N = 2000 and bandwidth of 1 GHz, based on ASICs fabricated in a 90 nm CMOS process, is presented. The cross-correlator proper (excluding per-antenna processing) is estimated to consume less than 35 kW.

Description: We present the INGV (Italian National Institute of Geophysics and Volcanology) geodetic research infrastructure and related facilities, dedicated to the observation and monitoring of current deformation of the plate boundary between Africa and Eurasia. The recent increase of continuous GPS (CGPS) stations in the Central Mediterranean plate boundary zone offers the opportunity to study in detail the present-day kinematics of this actively deforming region. For answering all the open questions related to this complex area, INGV deployed a permanent, integrated and real-time monitoring CGPS network (RING) all over Italy. The RING network (http:/ring.gm.ingv.it) is now constituted by more than 150 stations. All stations have high quality GPS monuments and most of them are co-located with broadband or very broadband seismometers and strong motion sensors. The RING CGPS sites acquire at 1Hz and 30s sampling rates (some of them acquire at 10 Hz) and are connected in real-time to the INGV acquisition centers located in Roma and Grottaminarda. Real-time GPS data are transmitted using different systems, such as satellite systems, Internet, GPRS/UMTS and wireless networks. The differentiation of data transmission type and the integration with seismic instruments makes this network one of the most innovative CGPS networks in Europe. Furthermore, the INGV data acquisition centers acquire, archive and analyze most of the Italian CGPS stations managed by regional or national data providers (such as local Authorities and nation-wide industries), integrating more than 350 stations of the CGPS scientific and commercial networks existing in the Italian region. To manage data acquisition, storage, distribution and access we developed dedicated facilities including new softwares for data acquisition and a web-based collaborative environment for management of data and metadata. The GPS analysis is carried out with the three main geodetic-quality softwares used in the GPS scientific community: Bernese GAMIT an GIPSY-OASIS. The resulting daily solutions are aligned to the ITRF2005 reference frame. Stable plate reference frames are realized by minimizing the horizontal velocities at sites on the Eurasia and Nubia plates, respectively. The different software-related solutions consistency RMS is within 0.3 mm/yr (Avallone et al., 2010). The solutions are then evaluated with regard to the numerous scientific motivations behind this presentation, ranging from the definition of strain distribution and microplate kinematics within the plate boundary, to the evaluation of tectonic strain accumulation on active faults. The RING network is strongly contributing to the definition of GPS velocity field in the Italian region, and now is able to furnish a newly and up to date view of this actively deforming part of the Nubia-Eurasia plate boundary. INGV is now aiming to make the RING (and integrated CGPS networks) data and related products publicly available for the scientific community. We believe that our network represents an important reality in the framework of the EPOS infrastructure and we strongly support the idea of an European research approach to data sharing among the scientific community. We will present (a) the current CGPS site distribution, (b) the technological description of the data acquisition, storage and distribution at INGV centers, (c) the results of CGPS data analysis, and (d) the planned data access for the scientific community.

Description: Published

Description: Vienna, Geophysical Research Abstracts Vol. 13, EGU2011-8626, 2011

Description: 1.9. Rete GPS nazionale

Description: 3.2. Tettonica attiva

Description: open

Description: Geographic data sharing and collection are becoming key activities among geological and geophysical studies worldwide, and the recent increase of infrastructures is demanding to scientific and civil community an effort to manage and disseminate their products as efficiently as possible. With this effort in mind, INGV began some years ago to collaborate with civilian and commercial subjects in order to promote the integration and sharing of data from GNSS (Global Navigation Satellite System) networks existing in Italy. Since 2004, INGV deployed a permanent, integrated and real-time monitoring CGPS network (RING, Rete Integrata Nazionale GPS, http://ring.gm.ingv.it), which is now constituted by about 170 stations all over Italy (Selvaggi et al., 2006; Avallone et al, 2010). All stations have high quality GPS monuments (D’Ambrosio, 2007; Minichiello et al., 2010) and most of them are co-located with broadband or very broadband seismometers and strong motion sensors. This scientific network is aimed to monitor crustal deformation in Italy in order to study earthquake deformation processes, from interseismic strain accumulation to rupture processes, and is giving an effective contribute to Italian Civil Protection for seismic hazard monitoring. Moreover, in the last years, local Authorities, nation-wide industries and other scientific institutions started to establish GPS/GNSS networks all over the Italian territory mainly for cartographic and positioning purposes. More than 500 CGPS stations are actually operating in Italy. The INGV acquire and analyze most of these networks, promoting at the same time actions to integrate the RING with the ones managed by regional and national data providers (D’Anastasio et al., 2010). The Regione Calabria in 2009 planned and established a network of 17 CGPS stations for cartographic and civil protection purposes covering the Calabria region (hereafter ReCal network). The CGPS stations are good quality monument connected in real time and, in the next future, will start to furnish to the civil community a positioning service. In order to share the RING and ReCal data and relative products, a synergy between the CNT-INGV (Centro Nazionale Terremoti) and the Regione Calabria started in 2011. An official agreement between the two institutions state the sharing of CGPS data, the collaboration between CNT-INGV and Regione Calabria to test the efficiency and the positioning service of ReCal network, and the contribution of ReCal network to scientific monitoring of Calabria, one of the most seismically active region in Italy. Moreover, this agreement included also the commissioning of the ReCal network and of its positioning services performed by CNT-INGV. Figure 1 shows the GPS and GNSS stations currently operating in Italy. In the inset it could be noticed how the RING and ReCal networks are integrated in order to have the best spatial coverage of the Calabrian territory. We will present the first results of the agreement between INGV-CNT and Regione Calabria, and of the commissioning of ReCal network. Moreover, we will focus on the infrastructure already existing and developed by CNT-INGV to manage data acquisition, storage, distribution and access (Cecere, 2007; Cardinale et al., 2010; Falco, 2006; 2008; Memmolo et al., 2010; Pignone et al., 2009). INGV developed dedicated facilities including new softwares for data acquisition and a web-based collaborative environment for management of data and metadata. These facilities are used to manage data coming from the RING as well as from agreements with ReCal and other CGPS networks in Italy. We believe that this infrastructure represents an important reality in the framework of GNSS data sharing development in Italy.

Description: Published

Description: Arcavacata di Rende (Cosenza), Italy

Description: 1.9. Rete GPS nazionale

Description: open

Description: Istituto Nazionale di Geofisica e Vulcanologia, Dipartimento Protezione Civile

Description: Published

Description: 1.1. TTC - Monitoraggio sismico del territorio nazionale

Description: 1.9. Rete GPS nazionale

Description: open